diff --git a/contracts/MinterFactory.sol b/contracts/MinterFactory.sol
index 630e79b..8900385 100644
--- a/contracts/MinterFactory.sol
+++ b/contracts/MinterFactory.sol
@@ -13,7 +13,7 @@ contract MinterFactory is Ownable, Initializable {
     IMintableERC721 public hero;
     IMintableERC721 public equip;
     IMintableERC721 public chip;
-    bool public publicMintAllowed;
+
 
     event TokenMinted(
         address contractAddress,
@@ -30,8 +30,8 @@ contract MinterFactory is Ownable, Initializable {
     /**
      * @dev mint function to distribute Blissful Elites Hero NFT to user
      */
-    function mintHeroTo(address to, uint256 tokenId) external {
-        require(publicMintAllowed || _msgSender() == owner());
+    function mintHeroTo(address to, uint256 tokenId) external onlyOwner{
+        require(to != address(0), 'to address can not be zero');
         hero.mint(to, tokenId);
         emit TokenMinted(address(hero), to, tokenId);
     }
@@ -39,8 +39,8 @@ contract MinterFactory is Ownable, Initializable {
     /**
      * @dev mint function to distribute Blissful Elites Equipment NFT to user
      */
-    function mintEquipTo(address to, uint256 tokenId) external {
-        require(publicMintAllowed || _msgSender() == owner());
+    function mintEquipTo(address to, uint256 tokenId) external onlyOwner{
+        require(to != address(0), 'to address can not be zero');
         equip.mint(to, tokenId);
         emit TokenMinted(address(equip), to, tokenId);
     }
@@ -48,16 +48,10 @@ contract MinterFactory is Ownable, Initializable {
     /**
      * @dev mint function to distribute Blissful Elites Chip NFT to user
      */
-    function mintChipTo(address to, uint256 tokenId) external {
-        require(publicMintAllowed || _msgSender() == owner());
+    function mintChipTo(address to, uint256 tokenId) external onlyOwner{
+        require(to != address(0), 'to address can not be zero');
         chip.mint(to, tokenId);
         emit TokenMinted(address(chip), to, tokenId);
     }
 
-    /**
-     * @dev function to allow user mint items
-     */
-    function allowPublicMint() public onlyOwner {
-        publicMintAllowed = true;
-    }
 }